1. Field of the Invention
The present invention relates to a power semiconductor device including power semiconductor chips and a power semiconductor module on which the power semiconductor device is mounted.
2. Description of the Background Art
A power semiconductor chip which functions as a thyristor, an IGBT (Insulated Gate Bipolar Transistor) or the like is obtained by selectively forming p-type and n-type impurity regions in a semiconductor substrate. The power semiconductor chip which is thus obtained is connected to a terminal board with lead portions, or the like and covered with a resin-sealed package, together with the terminal board or the like, to become a power semiconductor device.
The followings are among prior-art documents on such a power semiconductor device.
[Patent Document 1] Japanese Patent Application Laid Open Gazette No. 60-224256.
[Patent Document 2] Japanese Patent Application Laid Open Gazette No. 2-78265.
[Patent Document 3] Japanese Patent Application Laid Open Gazette No. 8-191130.
[Patent Document 4] Japanese Patent Application Laid Open Gazette No. 10-116959.
For example, FIGS. 1 and 2 of Patent Document 1 show thyristor chips 3 and 4. A power semiconductor chip, such as the thyristor chips 3 and 4, radiates heat in its operation, but Patent Document 1 gives no consideration on the heat radiation in operation.
FIGS. 1 and 2 of Patent Document 2 show a case where a plurality of power semiconductor chips in four to six pairs each consisting of two chips are mounted on a circuit component mounting portion 25. In the constitution, however, a plurality of power semiconductor chips in pairs of two are arranged closely to one another and therefore are susceptible to an ill effect of heat radiated from one another. Specifically, when one of the pair of power semiconductor chips has a high heating value, for example, there is a possibility that the heat radiation may increase the operating temperature of the other chip. Therefore, it can be said that Patent Document 2 also gives no consideration on heat radiation in operation.
None of Patent Documents 1 to 4 discusses heat radiation in a case where a plurality of power semiconductor devices on which the power semiconductor chips are mounted are collected in module.
In consideration of the above circumstances, the present invention is intended to provide a power semiconductor device and a power semiconductor module for improving a dissipation effect of heat radiated in operation of the power semiconductor chips.